In an office information environment, due to the widespread use of computer, software, and network, it became possible to accelerate and share information processing. Digitization of information is excellent in terms of storage, accumulation, retrieval, etc. of information, however, a paper medium is superior in terms of display (particularly viewability) and transfer of information. Therefore, as digitization of information is proceeding, the amount of paper used is increasing. On the other hand, reduction of energy consumption typified by CO2 emission is an urgent need in various fields. If a paper medium which is used for temporary display or transfer of information can be recycled, a large contribution can be made to the reduction of energy consumption.
As a technique capable of recycling a paper medium by erasing an image from the paper medium having the image formed thereon, a decolorizable toner is known. With the use of such a decolorizable toner, by heating the toner to a given temperature, a color developable compound and a color developing agent in the ink are dissociated from each other to decolorize the toner, whereby an image is erased.
As the decolorizable toner, a toner produced by a pulverization method is known, however, a plurality of components such as a color developable compound and a color developing agent are handled in a solid phase, and therefore color developing and erasing reactions are neither prompt nor sufficient in some cases. Accordingly, as a toner capable of developing and erasing a color more promptly, a decolorizable toner in which a color developable compound and a color developing agent are encapsulated is proposed.